“What Machine is it,” young Cherrycoke later bade himself goodnight, “that bears us along so relentlessly? We go rattling thro’ another Day,— another Year,— as thro’ an empty Town without a Name, in the Midnight . . . we have but Memories of some Pause at the Pleasure-Spas of our younger Day, the Maidens, the Cards, the Claret,— we seek to extend our stay, but now a silent Functionary in dark Livery indicates it is time to re-board the Coach, and resume the Journey. Long before the Destination, moreover, shall this Machine come abruptly to a Stop . . . gather’d dense with Fear, shall we open the Door to confer with the Driver, to discover that there is no Driver, . . . no Horses, . . . only the Machine, fading as we stand, and a Prairie of desperate Immensity. . . .”
The last lines of Ch. 35 of Thomas Pynchon’s novel Mason & Dixon seem to reiterate (what I take to be) the novel’s central question.